Development of SiC/(W, Ti)C gradient ceramic nozzle materials for sand blasting surface treatments

A model for the design of gradient ceramic nozzle materials is presented. The purpose is to reduce the tensile stress at the entry region of the nozzle during sand blasting processes. A (W, Ti)C/SiC gradient ceramic nozzle material, GN-1, was accordingly synthesized by hot pressing according to the design result. The residual thermal stress of the (W, Ti)C/SiC gradient ceramic nozzle in the fabricating process was calculated by means of the finite element method (FEM). The design of composition distribution of the gradient ceramic nozzle was carried out with the aim of partial relaxation of the stress resulting from external loadings by residual thermal stress. The erosion behavior of the gradient ceramic nozzle was investigated in comparison with the common ceramic nozzles. It is suggested that gradient structure in ceramic nozzles is an effective way to improve the erosion wear resistance over the common ceramic nozzles.